Alarm systems are major devices of monitoring systems or control systems of technical installations, for example power stations or production installations, and they are important aids for the operating personnel, in order to identify installation or process states which involve immediate action. The method of operation of the alarm systems for determining and displaying installation or process states is governed by alarm messages, that is to say for example by defined—for the purposes of alarm configuration—limit values of process variables. These alarm messages are made available to the operators of the installations in many different ways.
Since both individual components and subsystems of a control system are designed to generate alarms, that is to say a large number of alarms may occur, alarm systems are designed to operate effectively. They are intended to make operating personnel aware of dangerous situations, and to propose steps to avoid or overcome danger situations. Steps such as these are intended to return the respective process to normal operation. If too many alarms are generated during serious situations, the operator may possibly be confused, and alarms which are actually important may remain unidentified or ignored in the flood of alarms. This situation has been known, as well as many efforts to optimize alarm systems.
For example, commercial alarm analysis packets are known for generating KPIs (Key Performance Indicators) by analysis of recorded historical data, and these can help to optimize alarm systems. For example, such analyses can be used to determine very frequent alarms from historical recordings, as well as intermittent alarms, which occur frequently at very short time intervals, or else simple correlations, in which case the number of times that two alarms occur together at short intervals is counted.
When alarm systems are being designed or revised, the configuration process can be carried out manually, under the basis of process knowledge and simple statistics. However, in this case, the options to use the experience of operating personnel or knowledge from stored alarm events can be very limited. Continuous improvement efforts are directed to reducing the number of alarms, for example in serious situations as well, for example below the limits recommended by the EEMUA (Engineering Equipment and Materials Users' Association). It is self-evident that major alarms should not be suppressed.